All,
A must read:
Recieved this in email format from the Thistle mail list. It is very well written, much easier to understand then others I've heard try and explain it. He is reponding to someone having a problem pointing.
Happy Reading...
##########################################
For some reason, you included me as an addressee in your question
about pointing. I am no expert on pointing, but sometimes some-
one who has recently struggled with a problem can be more of a
help than an expert. Let me give it a stab.
I had learned to sail in a world of stiff masts and soft sails, I
had been away from sail boats for a number of years, and only
started sailing again about ten years ago. I am having a lot of
trouble adapting to the new world of stiff sails and flexible
masts. Two years ago, I attended a coaching clinic in Indian-
apolis. In the beginning, we were asked what we wanted to get
out of the clinic. My answer was "I can't point, I need help
with that" I learned a few things there that started me thinking
in the right direction.
Now let me relate some of the realizations I have had and some of
the ways my thinking has changed over the last few years. If any
one of these rings a bell with you, good. I do know that I point
a lot better now than I did. I also know that I still have a lot
to learn. Hints, clarifications or corrections from the experts
are welcome.
Keeping the boat on an even keel does make a difference. A big
difference. The boat with a 15 degree heel and a little tug on
the helm may "feel" like it's working in harmony with the forces
of nature. But it's really laboring under poorly balanced
forces. It may appear graceful to the spectator on shore, but
the upright boat cuts much more efficiendly through the air and
the water. Going up wind, keep the sails over the boat and not
out over the water
I had a lot of trouble seeing the shape of the stiff sails and
"seeing" how the wind was responding to them. I had to learn to
look at the telltails on the jib. I got a pencil and drew four
horizontal lines across the main, perpendicular to the luff and
passing through each batten. Then, along each line made some
reference points, 30, 40, & 50 % of the way back. This lets me
better see where the curvature of the sail is. The tuning guides
tell where the deepest point of the curvature should be. In-
creasing luff tension (cunningham) reduces the overall draft of
the sail and makes the deepest part of the draft appear to move
forward, Increasing the leech tension (mainsheet and/or vang)
will will do the same, but make the deepest point seem to move
aft. Increased wind loading increases the draft and seems to
move it aft.
In setting the jib, I usually have it sheeted in so the foot of
the sail comes in contact with the inboard side of the rail about
two feet back from the tack. The jib sheet turning block is
positioned to give the correct slot as seen through the little
window in the main.
Now, with the jib set like this, I steer by the telltales. From
my position at the helm, I can only see the middle and lower
ones. The two leeward telltales I have streaming at all times.
The windward ones are a different story. I find that as I head
up, the middle one breaks before the lower one. I steer so the
lower one is streaming and the middle one is at the point where
it can't decide whether to lift or stream.
I was not sheeting the main tightly enough upwind. The upper
portion of the sail was falling off to leeward. Overall, the
sail had too much belly in it. Yes, curvature of the sail is
what deflects the wind and makes the boat go. But too much
curvature can get in the way of a fast moving air stream and
actually slow things down. Pull down on the boom to bring the
top of the luff back in line with the lower portion. You will
probably see that the top batten is hooked a little to windward.
This is OK as long as it doesn't hook too far. Comparing the
masthead wind indicator with the head of the sail may make you
think you are sheeted too tightly, or that you are sailing too
low. This isn't really so. Don't steer by the mast head
indicator; steer by the jib telltales.
If the end of the boom is a foot above the traveller, your main
sheet is too loose.
I have a set of Proctor sails, and with them, outhaul makes a
difference. The amount of outhaul needed varies with wind
strength. I set the outhaul so that the seam in the foot of the
sail is 3" from the boom slot. I use the length of my fingers to
measure. If the wind increases and puts more pressure on the
sail, that seam will be pulled away from the boom. I tighten the
outhaul to draw the seam back to 3" from the slot. Similarly, if
the wind decreases and the overall loading on the sail lessens,
the foot of the sail will appear to tighten up. The outhaul
needs to be loosened to bring it into balance with the rest of
the sail and let that bottom seam out to its 3" position.
A couple of funny things about outhaul: Moving the clew farther
out on the boom changes the leverage between the mainsheet and
the leech. Also, pulling horizontally on the sail fabric shortens
it in the vertical direction. Kind of like the way a rubber band
gets skinnier when you stretch it. Outhaul tension enhances the
ability of the mainsheet to develop leech tension.
I am saying this not to tell you that you have to constantly be
checking and adjusting the outhaul, but to illustrate how the
wind affects the shape of the sail and what you can do in
response to it.
A lot of what I have written here is in the tuning guides that
come from the sailmakers and has been there all along. My
problem is that it really takes a long time for this stuff to
sink in. The first chapter of "Performance Sailing" by Stephen
Colgate has a pretty clear layman's discussion of sail shape and
how it is affected by strains in one direction or another.
"Sailboat Racing with Greg Fisher" by Tom Hubbel is the good all
around resource.
Books alone won't do it. What really helps is to get someone who
is better than you to sail with you on your boat. Watch him
(her) sail it. Let him watch you sail it. Talk to each other
about what each of you are doing and thinking
A must read:
Recieved this in email format from the Thistle mail list. It is very well written, much easier to understand then others I've heard try and explain it. He is reponding to someone having a problem pointing.
Happy Reading...
##########################################
For some reason, you included me as an addressee in your question
about pointing. I am no expert on pointing, but sometimes some-
one who has recently struggled with a problem can be more of a
help than an expert. Let me give it a stab.
I had learned to sail in a world of stiff masts and soft sails, I
had been away from sail boats for a number of years, and only
started sailing again about ten years ago. I am having a lot of
trouble adapting to the new world of stiff sails and flexible
masts. Two years ago, I attended a coaching clinic in Indian-
apolis. In the beginning, we were asked what we wanted to get
out of the clinic. My answer was "I can't point, I need help
with that" I learned a few things there that started me thinking
in the right direction.
Now let me relate some of the realizations I have had and some of
the ways my thinking has changed over the last few years. If any
one of these rings a bell with you, good. I do know that I point
a lot better now than I did. I also know that I still have a lot
to learn. Hints, clarifications or corrections from the experts
are welcome.
Keeping the boat on an even keel does make a difference. A big
difference. The boat with a 15 degree heel and a little tug on
the helm may "feel" like it's working in harmony with the forces
of nature. But it's really laboring under poorly balanced
forces. It may appear graceful to the spectator on shore, but
the upright boat cuts much more efficiendly through the air and
the water. Going up wind, keep the sails over the boat and not
out over the water
I had a lot of trouble seeing the shape of the stiff sails and
"seeing" how the wind was responding to them. I had to learn to
look at the telltails on the jib. I got a pencil and drew four
horizontal lines across the main, perpendicular to the luff and
passing through each batten. Then, along each line made some
reference points, 30, 40, & 50 % of the way back. This lets me
better see where the curvature of the sail is. The tuning guides
tell where the deepest point of the curvature should be. In-
creasing luff tension (cunningham) reduces the overall draft of
the sail and makes the deepest part of the draft appear to move
forward, Increasing the leech tension (mainsheet and/or vang)
will will do the same, but make the deepest point seem to move
aft. Increased wind loading increases the draft and seems to
move it aft.
In setting the jib, I usually have it sheeted in so the foot of
the sail comes in contact with the inboard side of the rail about
two feet back from the tack. The jib sheet turning block is
positioned to give the correct slot as seen through the little
window in the main.
Now, with the jib set like this, I steer by the telltales. From
my position at the helm, I can only see the middle and lower
ones. The two leeward telltales I have streaming at all times.
The windward ones are a different story. I find that as I head
up, the middle one breaks before the lower one. I steer so the
lower one is streaming and the middle one is at the point where
it can't decide whether to lift or stream.
I was not sheeting the main tightly enough upwind. The upper
portion of the sail was falling off to leeward. Overall, the
sail had too much belly in it. Yes, curvature of the sail is
what deflects the wind and makes the boat go. But too much
curvature can get in the way of a fast moving air stream and
actually slow things down. Pull down on the boom to bring the
top of the luff back in line with the lower portion. You will
probably see that the top batten is hooked a little to windward.
This is OK as long as it doesn't hook too far. Comparing the
masthead wind indicator with the head of the sail may make you
think you are sheeted too tightly, or that you are sailing too
low. This isn't really so. Don't steer by the mast head
indicator; steer by the jib telltales.
If the end of the boom is a foot above the traveller, your main
sheet is too loose.
I have a set of Proctor sails, and with them, outhaul makes a
difference. The amount of outhaul needed varies with wind
strength. I set the outhaul so that the seam in the foot of the
sail is 3" from the boom slot. I use the length of my fingers to
measure. If the wind increases and puts more pressure on the
sail, that seam will be pulled away from the boom. I tighten the
outhaul to draw the seam back to 3" from the slot. Similarly, if
the wind decreases and the overall loading on the sail lessens,
the foot of the sail will appear to tighten up. The outhaul
needs to be loosened to bring it into balance with the rest of
the sail and let that bottom seam out to its 3" position.
A couple of funny things about outhaul: Moving the clew farther
out on the boom changes the leverage between the mainsheet and
the leech. Also, pulling horizontally on the sail fabric shortens
it in the vertical direction. Kind of like the way a rubber band
gets skinnier when you stretch it. Outhaul tension enhances the
ability of the mainsheet to develop leech tension.
I am saying this not to tell you that you have to constantly be
checking and adjusting the outhaul, but to illustrate how the
wind affects the shape of the sail and what you can do in
response to it.
A lot of what I have written here is in the tuning guides that
come from the sailmakers and has been there all along. My
problem is that it really takes a long time for this stuff to
sink in. The first chapter of "Performance Sailing" by Stephen
Colgate has a pretty clear layman's discussion of sail shape and
how it is affected by strains in one direction or another.
"Sailboat Racing with Greg Fisher" by Tom Hubbel is the good all
around resource.
Books alone won't do it. What really helps is to get someone who
is better than you to sail with you on your boat. Watch him
(her) sail it. Let him watch you sail it. Talk to each other
about what each of you are doing and thinking